Conservative Treatment using Blood Flow Restriction in Individuals with Complete Anterior Cruciate Ligament Rupture: Protocol for a Randomised Clinical Trial

Background Inadequate long-term outcomes are common following both surgical and non-surgical management of anterior cruciate ligament (ACL) rupture. Emerging evidence suggests that a bracing protocol may facilitate ligamental healing; however, a period of immobilization can induce muscle atrophy. This study aims to investigate potential benefits of adding blood flow restriction (BFR) training to the conservative treatment of ACL rehabilitation. Methods This is a double-blinded, two-arm randomised clinical trial. Participants in the intervention group will follow an exercise protocol using BFR training, while participants in the control group will follow the same protocol with sham BFR. Both groups will follow the same splint protocol. Individuals aged between 18 and 40 years with an acute or subacute complete ACL tear confirmed by imaging will be eligible to participate. Discussion Emerging evidence suggests that a conservative period of joint immobilisation, positioning the knee reduces the distance between the two torn ligament ends, may promote ACL healing after a complete rupture. However, brace use can result in muscle atrophy. BFR exercises may play an important role during this period of immobilisation and restricted movement. Positive results of exercise under BFR, in combination with a brace, can serve as an alternative treatment for participants with acute or subacute complete ACL tear, potentially reducing recovery time or even avoiding surgery. Trial registration: This protocol was approved by the Cyprus National Bioethics Committee (ΕΕΒΚ/ΕΠ/2024/70) and registered on ClinicalTrials.gov (Registration number: NCT06727344).